Answer
$x=27$
Work Step by Step
Recall:
If $y$ varies directly as $x$ then, $y=kx$ where $k$ is the constant of variation.
Since $x=9$ w3&=hen $y=3$, then:
\begin{align*}
y&=kx\\\\
3&=k(9)\\\\
\frac{3}{9}&=\frac{k(9)}{9}\\\\
\frac{1}{3}&=k
\end{align*}
Thus, the direct variation's equation is:
$$y=\frac{1}{3}x$$
To find the value of $x$ when $y=9$, substitute these values into the equation above to obtain:
\begin{align*}
y&=\frac{1}{3}x\\\\
9&=\frac{1}{3}x\\\\
3(9)&=\frac{1}{3}x \cdot 3\\\\
27&=x
\end{align*}
